Is CVE-2021-22886 in the CISA KEV catalog?

No. CVE-2021-22886 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-22886?

CVE-2021-22886 has a CVSS v3 base score of 6.1 (MEDIUM).

What is the EPSS score for CVE-2021-22886?

CVE-2021-22886 has an EPSS score of 1.70% (74th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-22886?

Upgrade rocket.chat to 3.10.5 or later.

CVE & CISA-KEV Catalog

CVE-2021-22886

MEDIUMEPSS 74th pctl

6.1

CVSS v3

NVD

Description

Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app.

CWE-79Cross-Site Scripting (XSS)

How to fix

Remediation Available

rocket.chatNVD

Affected:>= 3.10.0, < 3.10.5Fixed in:3.10.5CVE-2021-22886derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeChanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Exploit Intelligence

1.70%probability of exploitation in 30 days

74thpercentile

Elevated risk: more likely to be exploited than 74% of all known CVEs.

References

Patch1

github.com

Vendor Advisory1

docs.rocket.chat

Third-Party Advisory1

hackerone.com

Related Vulnerabilities

Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-11022	Medium	6.9	99%	-	Fix
CVE-2019-3929	Critical	9.8	99%	KEV	Fix
CVE-2020-9496	Medium	6.1	99%	-	-
CVE-2023-28341	Medium	6.1	99%	-	Fix
CVE-2018-12998	Medium	6.1	98%	-	-
CVE-2025-4123	High	7.6	98%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.